1. Field of the Invention
The invention concerns a method of rebooting terminals connected to a local area network and devices (concentrators and terminals) for implementing the method. If relates more particularly to local area networks which provide a remote power supply to the terminals, especially Ethernet local area networks capable of providing a remote power supply to the terminals.
2. Description of the Prior Art
Many different types of terminal can be connected to this kind of network (for example telephones which use the Internet protocol). It is sometimes necessary to reboot some terminals so that they restart with a new configuration, for example after a network administrator has commanded the downloading of software. It is often the case that the only way to reboot a terminal is to switch it off manually and then to switch it on again. Processors and logic circuits include a device that reboots them automatically when the supply voltage increases from zero to its nominal value.
It is sometimes necessary to switch off some of the terminals or all of the terminals for network maintenance operations. Usually someone goes to each terminal to switch it off, or asks each user to switch off their terminal. This operation is time-consuming if there are many terminals to be switched off. It is also desirable to be able to reboot the concentrators.
A device for rebooting terminals, connected to a local area network, by broadcasts over the network data packets commanding interruption of the local power supply in each terminal and possibly in the concentrators is known in the art. This device has the drawback that it is inoperative if executing software has caused the terminal to crash (for example because of accidental loopback).
The object of the invention is to propose a method and simpler devices for rebooting many terminals and concentrators from a central point that are not subject to this problem.